"This lady's for turning", created by Krow Communications, highlights issues that the prime minister has promised but later made a U-turn on, such as calling a snap general election and changes to national insurance.
It shows May standing outside 10 Downing Street to the left of the door waving as she poses for photos, but she then realises she should be on the other side and rushes over.
This shot is repeated over again as the Benny Hill theme tune plays over the top, with copy questioning May’s "strong and stable" leadership.
The ad is available on Labour's social media channels.
The general election will take place in five weeks’ time on 8 June.